What are the 3 types of symbiotic relationships and give an example for each?

Commensalism, mutualism, and parasitism.

Explanation:

Commensalism: It is defined as the type of symbiotic relationship where one species gets benefits, and other species neither harmed nor helped. For example tree frogs use plants as a protection for themselves.

Mutualism: It is defined as the type of symbiotic relationship where both species gets benefits from each other. For example legumes, and nitrogen fixing bacteria.

Parasitism: It is defined as the type of symbiotic relationship where one species gets benefit, and other species is harmed. For example ticks that lives on cats, and dogs are known as parasites.

organisms that lack symmetry are called asymmetrical and belong to phylum porifera/sponges.

organisms with specialized stinging cells belong to phylum cnidaria. stinging cells are called cnidoblast cells.

cnidarians show two morphological forms : polyp (sessile) and medusa (mobile)

filter feeding is observed in porifera members.  

alternation of generation is observed in coelenterata or cnidaria. there is alternation of asexual polyp form and sexual medusoid form. it is also referred as metagenesis.

b a mature ovary of a plant.